PRINCIPLES OF Water Chemistry
Problem (100 points): A water solution contains 10-3 M NaHCO3, 10-2 M HCl, and 10-2 M NaOH. Assuming ideal system:
- Identify all possible chemical species present at equilibrium
- Write all relevant chemical reactions involved and their corresponding equilibrium constant equations and values (the Keq values should be in lecture notes, textbook, etc.)
- Write all relevant mass balance equations
- Write the charge balance equation
- Determine the narrowest range of pH for this solution using the excel spreadsheet approach
- For the same solution, use the protonation sequence approach to identify the potential dominant species.
- Prepare a TABLEAU using the determined dominant species as components
- Determine the proton condition equation.
- Prepare a log C – pH diagram and determine the equilibrium pH (as intersection of LHS and RHS) as well as the concentrations of all species at the determined pH.
- Using MINTEQ, solve the same problem and:
- Report (i) the pH (include the screenshot) and (ii) the concentrations and activities of all species you have listed under the above step-1 (in this case, export to excel and include in the report as edited table).
- For relevant species, compare the concentrations obtained with MINTEQ to those determined in the above step 9.
- Finally, determine the activity coefficient () for each of the species identified in step-1.
Please note that for this step 10, you are expected to present your results as a written report describing each step used and including screenshots of relevant MINTEQ screens.